Terminal block



R. R. HAUGH.

TERMINAL BLOCK.

APPLICATION FILED SEPT, 23. 1920.

Patented Aug. 16, 1921.

PATENT OFFICE.

RAYMOND R. HAUGH, OF CHICAGO, ILLINOIS. I

TERMINAL BLOCK.

Specification of Letters Patent.

Patented Aug. 1c, 1921.

Application filed September 23, 1920. Serial No. 412,275.

To all whom it may concern:

Be it known that I, RAYMOND R. HAUGH, a citizen of the United States ofAmerica, and a resident of Chicago, county of Cook, and State ofIllinois, have invented certain new and useful Improvements in TerminalBlocks, of which the followingis a specification.

The main objects of this invention are to provide an improved form ofterminal block for use with electrically heated appliances; to providean improved form of switch within said block for breaking and closingthe circuit; to provide means incorporated in the block forautomatically opening said switch when the heat of said appliancereaches a desired predetermined limit, and to provide means for manuallyoperating said switch independently of said automatic means. Q

An illustrative embodiment'of this invention is shown in theaccompanying drawin s, in which- *igure 1 is a longitudinal section ofthe terminal block.

Fig. 2 is a section on the line 22 of Fig. l.

Fig.3 is a side elevation, partly in section, taken on the line 3-3 ofFig. 1.

Fig. 4 is a fragmentary section showing a certaln part of the switchmechanism in detail.

v Electrically heated devices such as irons, toasters, etc., haveheretofore been provided with thermostatic means for breaking thecircuit when the temperature of the heating device arrives at somepredetermined point. These circuit breakers are separate from the usualterminal block or attachment plug through which the current reached theheating element. The present invention relates to such a terminal blockhaving incorporated therein an improved thermostatically controlledcircuit breaker. In addition to the automatic action provided for by,thethermostatic element, means are provided on the terminal block wherebythe circuit may be manually opened or closed.

The improved form of terminal block as shown in the drawings comprises abody part 1 composed of suitable insulating material and comprising apair of complementary members 2 which are detachably secured together bybolts 3, the opposed faces of the members 2 being grooved to provideseats for the terminals and switch mechanism.

A pair of socket terminals 4 and 5 are seated in spaced relation at theouter end of the block to receive the prongs which form the plug of theiron, toaster or other electrically heated device, (not shown). Theterminal 4 is directly connected to one of the conductors 6 and theterminal 5 is connected to the other conductor 7 by the switch mechanism8 whereby the circuit may be opened and closed.

The switch mechanism for breaking the circuit either manually orautomatically comprises a switch blade 9 pivotally secured at its innerend to the block by a pin 10 which is connnected to the terminal 5 by aconductor 11. The conductor 7 is fastened to a spring contact clip 12which is rigidly secured to the block in aposition to receive and clampthe outer end of the blade to close the circuit. Coiled around the pin10 is a spring 13 which bears against the inner edge of the switch bladeso as to normally urge the blade out of contact with the clip 12 forbreaking the circuit.

An arm 14 is carried by the switch blade and is pivotally securedthereto by a pin 15. Angular movement of the arm 14 in a counterclockwise direction relatively of the switch blade is limited by ashoulder 16 which is struck up from one edge of the blade in position toengage the arm 14 on the side opposite the clip 12. The inner end of thearm isbent outwardly so as to extend to one side of the switch blade toform a lug 1?, and the outer end of the arm is formed to provide ahandle 18 which extends outwardly through a slot 19 in the block wherebythe blade may be manually shifted into and out of contact with thespring clip 12.

The means for retaining the switch in its closed position comprises athermostatic element 20 which is seated in a slot 21 formed on one sideof the block and which is rigidly secured at one end to one of themembers 2 by a pin 22. The free end of the thermostatic element isadapted to engagethe outer extremity of the lug 17 for retaining theblade in contact with the spring clip 12. The thermostatic elementcomprises a pair of metal strips rigidly secured together to preventrelative movement. .The two str ps are composed of different metalshaving different coefficients of expansion and the element is arrangedso that as the heat of the appliance increases beyond the deslredpredetermined limit the free end of the element will swing outwardlyaway'from the lug 17 thereby permitting the switch blade to be urgedaway from the contact clip by the spring 13. When the device is cooled'sufliciently the circuit may be closed by manually shifting the handle18 to bring the lug 17 again into engagement with the thermo staticelement. The circuit may be broken without regard to the heat of thedevice by manually shifting the arm 14: out of contact with the element20.

Although but one specific embodiment of this invention is herein shownand described, it will be understood that some of the details of theconstruction shown may be altered or omitted without departing from thespirit of this invention as defined by the following claims.

I claim:

1. A terminal block for electrically heated appliances having a bodyformed of insulating material, aswitch blade pivotally mounted on saidblock, means for normally urging said switch to its open position, athermostatic element having one end rigidly secured to said block andhaving its other end arranged to hold said switch in its closed positionagainst the action of said means, said element being disengaged fromsaid switch blade when the heat of said appliance reaches apredetermined limit.

2. A terminal block for electrically heated appliances having a bodyformed of insulating material, a switch blade pivotally mounted withinsaid block, means for normally urging said blade to its open posi tion,a lug formed on the said blade adjacent its pivot, and a thermostaticelement having one end rigidly secured to said block, the free end ofsaid element being adapted to engage said lug so as to hold said bladein its closed position against the action of said means, said elementbeing disengaged from said lug to release said blade when the heat ofsaid appliance reaches a predetermined limit.

3. A terminal block for electrically heated appliances having a bodyformed of insulating material, a switch blade pivotally mounted withinsaid block, an arm pivotally mounted on said blade, means for limitingthe relative movement of said arm and blade, other means for normallyurging said blade to its open position, and a thermostatic elementhaving one end rigidly secured to said block, the free end of saidelement being adapted to engage one end of said pivoted arm so as tohold said switch blade in its closed position against the action of saidother means, said element beswitch blade to its open position, and athermostatic element having one end rigidly secured to said block, thefree end of said element being adapted to engage the inner end of saidpivoted arm so as to hold said switch blade in ,its closed positionagainst the action of said means, said element being disengaged fromsaid arm to release said blade' when the heat of said appliance reachesa predetermined degree, the outer end of said pivoted arm being formedto provide a handle extending outside of said block whereby said arm maybe manually disengaged fromsaid thermostatic element independently ofthe heatof said appliance.

5. A terminal block for electrically heated appliances comprising a pairof separable members formed of insulating material, a pair of terminalscarried by said block, a switch blade connected to one of said terminalsand having one end pivotally secured to said block, a contact clipsecured to said block for receiving the free end of said blade, a springnormally urging said blade out of contact with said clip, an armpivotally mounted on said blade, a shoulder struck up from said switchblade for limiting the angular movement of said arm relatively of saidblade, and a thermostatic element having one end rigidly secured to saidblock, the free end of said element being adapted to engage the innerend of said pivoted arm so as to hold said switch blade in contact withsaid clip against the action of said spring, said element beingdisengaged from said arm to release said blade when the heat of saidappliance reaches a predetermined limit, the outer end of said pivotalarm being formed to provide a handle extending outwardly through a slotformed in said block whereby said arm may be manually disengaged fromsaid thermostatic element independently of the heat of said appliance.

Signed at Chicago this 18 day of Sept, 1920.

RAYMOND R. HAUGH.

